The idea that different media can work in conjunction to transmit a story, understood as a distributed narrative, is a new one and has partly been developed as a result of the technological evolution of media. On a basic level, it has been applied in education in a similar way for a long time. However, transmedia storytelling based on digital media is a very new concept for education, particularly for formal education. An "ad hoc" educational application entitled "The Ancestral Letter" was designed and subsequently tested in a secondary school to verify the interest of this concept. The results, which must be qualified by the specific circumstances of a single experience, show significant improvements in core aspects such as motivation, engagement and the improvement of some competencies.